If you have a stock K-340, the elastic adjusters are probably near useless. I replace those with more beefy elastic. I change the single entry cable to dual entry and eliminate the passing of signal through steel headband frame. To do this correct, a new clamp must be made along with a slot for the cable on the right cover (which I do both of). I recable via a sort of bypass path directly to the dynamic bass driver. This bypasses one set of internal wires, solder joints, PCB traces and in general sounds better. I change the front plastic screens to sound transparent fabric (shown above), which allows the sound waves to go to your ears rather than bounce around in a plastic mesh. You can see in the pic below this mod how open the drivers become to your ears (shown post cloth treatment). I change the internal damping to complete the mod.I do one VERY important driver tweak that no one else does, nor knows about :-)

Occasionally I offer a complete modded pair on Headphone Deals page (if there's none there, I have none for sale at that time).

An AKG K702 cable customer comment (thought this was funny and sums it up in short order… language cleaned up). " I'm going to cuss! FXXXING AMAZING!!!! I had doubts- FXXXING WOW! Right out of the box this cable lifted the veil that I DIDNT EVEN KNOW WAS THERE!!!!!!!! AMAZING "

The left entry side mini XLR cable is used on a number of AKG headphones, with a couple of the most popular (K702 & K271) as what I know it fits. There may be some others, but not sure what they are. I've pre-set the angle coming off the plug to help with stress at that spot (but still proper cable care on FAQ page)